The present invention relates to an automatic assembly apparatus, and more particularly to an automatic assembly apparatus of the type installed in a product assembly line of a manufacturing plant for assembling parts of a workpiece.
Typically, a number of individual stations are installed in a production line of an assembly plant for each step in the automatic assembly of automobile parts, such as engine cylinder blocks. Referring to FIG. 5, a large vertical column, such as 32 is erected for one or more stations, for performing the assembly operation with an assembling shaft head 33 of column 32. In assembling a part to a workpiece 34 at the assembling shaft head 33, it is necessary to supply or convey such part to the workpiece in a roundabout manner so as to avoid the column 32, which is positioned approximately in the center of assembly station 31. Such part is generally supplied along a course that deviates upwardly or sidewardly from the column 32.
Further, the above-mentioned conventional technique incorporates a system of installing an individual apparatus 31 for each station of the assembly line; and therefore, whenever it is required to change the station or to add a further station due to a change in the work or the addition of new work, all of the apparatus assigned to the station must be changed. Thus, the station changing or adding operation becomes quite complicated.
Further, since the parts assembled at each station are supplied in a roundabout manner to avoid the column 32 or the assembling shaft head 33 mounted thereon, the entire facility, which includes the incidental equipment such as the work carrying means, work pallet collecting means, control means and etc., has become complicated, thereby hindering the visibility of the assembly work in the production line.
Recently, a flexible system in which an articulated robot is provided at each station of the assembly line has been developed, for the assembly of small-sized workpieces, such as electronic parts, home electrical appliances and etc., but the articulated assembling robot has a wide operating range so that without a safety fence or the like arrangement, it is difficult for an operator to intuitively be aware of the operation range; and moreover, he cannot but feel some sense of difficulty while he works with the robot. Further, since the robot has an arm held in a cantileaver fashion, it is not suitable for handling heavy parts; although it is applicable to the handling of those parts that are of light weight.